The present invention provides a micro cellulose fiber complex in which an amine having an ethylene oxide/propylene oxide (EO/PO) copolymer part is bound, as a salt, to the carboxyl group of micro cellulose fibers having a carboxyl group content of 0.1 mmol/g or more, wherein the molecular weight of the EO/PO copolymer part is 700-10,000, and the content of PO in the EO/PO copolymer part is 1-70 mol%. This micro cellulose fiber complex exhibits high dispersibility with respect to resins, can express a strength enhancing effect, and is suitable as various filler agents.